The present invention relates to the packaging industry and more particularly to the packaging of pumpable substances, such as creams, milks, ointments and other emulsions, gels, more or less thick liquids, in particular for use in pharmaceutics, cosmetics or household maintenance.
Such substances are usually packaged in pots of easily handled sizes having a volume adapted to allow the user to repeatedly take portions of the substance over a more or less long period of time, usually about several weeks. Most often, these pots have a large opening to permit the user to take the product with his fingers. This exposes the substance remaining in the pot to pollutions by the surrounding air and the fingers of the user, and moreover causes evaporation of the more or less volatile components of the packaged substances.
To overcome these drawbacks, it has been proposed to enclose the substances to be distributed in containers having a deformable or movable wall so that the volume of the container gradually diminishes as the substance is taken off without entry of air. In such packages, the user exerts a pressure on the deformable or movable wall so as to expel a more or less variable amount of substance. This is the case of packages in the form of flexible tubes, pots having a piston or a lenticular diaphragm, for example those employed principally for food, hygienic or household maintenance products. Substances are also sold, above all toothpastes, in relatively rigid tubular containers in which the substance is protected from the air by a piston which moves, in the course of the distribution, in accordance with the diminishing volume of the remaining substance. The distribution is achieved by an elastically deformable bulge at the bottom of the container constituting a pump, provided with a check valve. Such a package is disclosed in particular in the German Federal Republic patent No. 1 210 149.
In these conventional packages, the measure of the substance delivered must be received in the hand, or on a brush or other exterior receptacle, which is often impractical since this immobilizes one hand or implies the presence of a nearby table or other support. Further, the distribution orifice is exposed to the air, with risk of deterioration and pollution of the exposed layer of substance. If a detachable cap is provided to avoid this drawback, this requires an additional operation with risk of losing the cap or soiling it if it drops on the floor. It must also be possible to place the cap on a support during the distribution of the substance. It is moreover usually difficult to construct such conventional packages from materials which are sufficiently transparent to enable one to see the level of the substance remaining in the container. Further, in conventional packages, the pump or other distributing means is actuated directly with the finger in the vicinity of the distribution orifice, which involves a risk of soiling the actuating finger with the expelled substance.
An object of the invention is to overcome the drawbacks of packages proposed heretofore and permit the industrial production of packages which are easier and cleaner to use, protect the substance remaining available from any exterior soiling, and possibly indicate the level of the substance in the container.